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United States Patent |
5,576,274
|
Patil
|
November 19, 1996
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Fuel and lubricant additives derived from dihydroxy-aromatic compounds
Abstract
The present invention relates to a novel process for the production of fuel
and lubricant additives useful as dispersants and multifunctional
viscosity modifiers wherein a dihydroxyaromatic compound is alkylated with
an olefinic polymer and then aminated in such a manner as to oxidize the
hydroxyl moieties of the dihydroxyaromatic compound to carbonyl groups.
Inventors:
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Patil; Abhimanyu O. (Westfield, NJ)
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Assignee:
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Exxon Chemical Patents Inc. (Linden, NJ)
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Appl. No.:
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406828 |
Filed:
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March 20, 1995 |
Current U.S. Class: |
508/560; 44/428; 508/563; 564/395; 564/403 |
Intern'l Class: |
C10M 149/12; C10L 001/22; C07C 229/62 |
Field of Search: |
564/395,403
44/426,427,428
252/51.5 R
|
References Cited
U.S. Patent Documents
3007785 | Nov., 1961 | Fareri et al. | 44/75.
|
3214472 | Oct., 1965 | Charle et al. | 564/403.
|
3682980 | Aug., 1972 | Braid et al. | 260/396.
|
3965182 | Jun., 1976 | Worrel | 564/403.
|
4238628 | Dec., 1980 | Cahill et al. | 568/736.
|
4708809 | Nov., 1987 | Davis | 252/51.
|
4740321 | Apr., 1988 | Davis et al. | 252/51.
|
5017299 | May., 1991 | Gutierrez et al. | 252/51.
|
5028394 | Jul., 1991 | Lowell, Jr. et al. | 422/58.
|
5113018 | May., 1992 | Kurano et al. | 564/403.
|
Foreign Patent Documents |
0487278A2 | May., 1992 | EP.
| |
PCT/US93/03119 | Apr., 1993 | EP.
| |
1104522 | Apr., 1959 | DE | 564/403.
|
1228972 | Nov., 1966 | DE.
| |
963263 | Jul., 1964 | GB.
| |
PCT/US92/00472 | Jan., 1992 | WO.
| |
PCT/US93/04991 | May., 1993 | WO.
| |
PCT/US93/12193 | Dec., 1993 | WO.
| |
Other References
Teintex, en 1981 Regroupe Au Sein De L'Industrie Textile, vol. 35, No. 5,
May 1970, Paris FR pp. 277-280 Riesz `Nouveaux Colorants De Cuve
Naphtoquinoniques` (Translation attached).
|
Primary Examiner: McAvoy; Ellen M.
Attorney, Agent or Firm: Walton; K. R.
Parent Case Text
FIELD OF THE INVENTION
This application is a continuation of U.S. Ser. No. 134,246, filed Oct. 8,
1993, now U.S. Pat. No. 5,399,277.
Claims
What is claimed is:
1. A process for the production of fuel and lubricant additives, said
process comprising:
providing an alkylated dihydroxyaromatic compound having been alkylated
with a polymer alkylating agent having a number average molecular weight
of at least about 700 and containing at least one reactive carbon-carbon
double bond; and
aminating said alkylated dihydroxyaromatic compound with at least one amine
under conditions effective in oxidizing the hydroxyl groups of said
alkylated dihydroxyaromatic compound to carbonyl groups.
2. The process of claim 1 wherein said dihydroxyaromatic compound is
selected from the group consisting of catechol and hydroquinone.
3. The process of claim 1 wherein said amine is at least one selected from
the group consisting of amines represented by the following structural
formulas:
##STR11##
wherein n is an integer of at least 1, s is a number from 2 to 6, t is a
number from 0 to 10, and R', R", and R'", and R.sup.IV are independently
selected from the group consisting of hydrogen; C.sub.1 to C.sub.25
straight or branched chain alkyl radicals; C.sub.1 to C.sub.12 alkoxy
C.sub.2 to C.sub.6 alkylene radicals; C.sub.2 to C.sub.12 hydroxy amino
alkylene radicals; and C.sub.1 to C.sub.12 alkylamino C.sub.2 to C.sub.6
alkylene radicals.
4. The process of claim 3 wherein R" and R'" further comprise a moiety of
the formula:
##STR12##
wherein each s and s' is the same or a different number of from 2 to 6,
and t and t' is the same or different and are each numbers of from 0 to
10, with the proviso that t+t' is not greater than 10.
5. The process of claim 1 wherein said amine is polyethyleneamine.
6. The process of claim 1 wherein said amine is selected from the group
consisting of diethylenetriamine and N,N-dimethylaminopropylamine.
7. The process of claim 1 wherein said polymer alkylating agent is selected
from the group consisting of an unsaturated ethylene/.alpha.-olefin
copolymer, an unsaturated propylene/butene-1 copolymer, and an unsaturated
homopolymer of an olefin monomer having four carbon atoms.
8. The process of claim 7 wherein said polymer alkylating agent is
unsaturated ethylene/.alpha.-olefin copolymer wherein the .alpha.-olefin
comprises four carbon atoms.
9. The process of claim 7 wherein said polymer alkylating agent comprises
at least about 30% combined terminal ethenylidene and ethenyl
unsaturation.
10. The process of claim 7 wherein said polymer alkylating agent has a
number average molecular weight of 1000 to 19,000.
11. A product formed by the process which comprises:
providing an alkylated dihydroxyaromatic compound having been alkylated
with a polymer alkylating agent having a number average molecular weight
of at least about 700 and containing at least one reactive carbon-carbon
double bond; and
aminating said alkylated dihydroxyaromatic compound with at least one amine
under conditions effective in oxidizing the hydroxyl groups of said
alkylated dihydroxyaromatic compound to carbonyl groups.
12. An oleaginous composition comprising a major amount of a lubricating
oil and a minor amount of the product of claim 11.
13. An oleaginous composition comprising a major amount of a fuel and a
minor amount of the product of claim 11.
14. The product according to claim 11, wherein the dihydroxyaromatic
compound is selected from the group consisting of catechol and
hydroquinone.
15. The product according to claim 11, wherein the amine is at least one
member selected from the group consisting of amines represented by the
following structural formulas:
##STR13##
wherein n is an integer of at least 1, S is a number from 2 to 6, t is a
number from 0 to 10, and R', R", and R'', and R.sup.IV are independently
selected from the group consisting of hydrogen; C.sub.1 to C.sub.25
straight or branched chain alkyl radicals; C.sub.1 to C.sub.12 alkoxy
C.sub.2 to C.sub.6 alkylene radicals; C.sub.2 to C.sub.12 hydroxy amino
alkylene radicals; and C.sub.1 to C.sub.12 alkylamino C.sub.2 to C.sub.6
alkylene radicals.
16. The product according to claim 11, wherein the polymer alkylating agent
comprises a polyalkene containing at least one carbon-carbon double bond
unsaturation.
17. The product according to claim 16, wherein the polyalkene has a number
average molecular weight of from 1000 to 19,000.
18. The product according to claim 16, wherein the polyalkene comprises at
least one member selected from the group consisting of .alpha.-olefin
homopolymers, .alpha.-olefin interpolymers, and ethylene/.alpha.-olefin
copolymers.
19. The product according to claim 18, wherein at least about 30% of the
polymer chains of the polyalkene have terminal ethenylidene unsaturation
or combined terminal ethenylidene and ethenyl unsaturation.
20. A substance useful as a fuel or lubricating additive having the
chemical formula selected from the group consisting of:
##STR14##
wherein POLY is a polymeric hydrocarbyl derived from a polymer having a
number average molecular weight of at least about 700 and containing at
least one reactive carbon-carbon double bond and N-Amine is an amine bound
to the ring structure via a nitrogen atom.
Description
The present invention relates to a novel process for producing fuel and
lubricant additives such as dispersants, viscosity modifiers, and
multifunctional viscosity modifiers by alkylating and then aminating
dihydroxyaromatic compounds, such as catechol and hydroquinone.
BACKGROUND OF THE INVENTION
Liston et al., U.S. Pat. Nos. 4,632,771 and 4,643,838 for NORMALLY LIQUID
C.sub.18 TO C.sub.24 MONOALKYL CATECHOLS refer to normally liquid
lubricating oil additives which provide both antioxidant and
friction-modifying properties when added to lubricating oil. In
particular, these patents relate to C.sub.18 to C.sub.24 alkyl catechol
lubricating oil additives which are normally liquid at typical storage
temperatures.
Werner et al., U.S. Pat. No. 4,265,833 for a PROCESS FOR THE PREPARATION OF
HYDROXY-DIPHENYLAMINES refers to a process for the preparation of
hydroxy-diphenylamines by condensation of dihydroxybenzene with an excess
amount of primary aromatic amine in the presence of a catalytic amount of
an acid at elevated temperature, wherein the excess aromatic amine and the
reaction product is distilled off from the reaction mixture in the
presence of a base.
Coupland et al., U.S. Pat. No. 3,592,820 for SUBSTITUTED CATECHOL SALTS OF
BENZOTRIAZOLES OR PHENYLHYDRAZINES refers to a compound which may be
produced by reaction of substituted catechol with phenylhydrazine,
substituted phenylhydrazine, benzotriazole, or substituted benzotriazole.
The reaction may be carried out in an inert solvent, such as a
hydrocarbon. The compounds are useful as antioxidants in lubricant
compositions.
Small, Jr. et al., U.S. Pat. No. 5,061,390 for DIETHYLAMINE COMPLEXES OF
BORATED ALKYL CATECHOLS AND LUBRICATING OIL COMPOSITIONS CONTAINING THE
SAME refers to lubricating oils containing a borated alkyl
catecholdiethylamine complex effective in reducing oxidation, wear, and
deposits in internal combustion engines.
Davis, U.S. Pat. No. 4,663,063 for ALKYL PHENOL AND AMINO COMPOUND
COMPOSITIONS AND TWO-CYCLE ENGINE OILS AND FUELS CONTAINING SAME refers to
a composition comprising the combination of (A) at least one alkyl phenol
of the formula
(R).sub.a --Ar--(OH).sub.b
wherein each R is independently a substantially saturated hydrocarbon-based
group of an average of at least about 10 aliphatic carbon atoms; a and b
are each independently an integer of one up to three times the number of
aromatic nuclei present in Ar with the proviso that the sum of a, b, and c
does not exceed the unsatisfied valences of Ar; and Ar is an aromatic
moiety which is a single ring, a fused ring or a linked polynuclear ring
having 0 to 3 optional substituents selected from the group consisting
essentially of lower alkyl, lower alkoxyl, carboalkoxy methylol or lower
hydrocarbon-based substituted methylol, nitro, nitroso, halo and
combinations of said optional substituents, and (B) at least one amino
compound with the proviso that the amino compound is not an amino phenol.
Lubricants and lubricating oil-fuel mixtures for two-cycle engines which
include the above compositions, and methods for lubricating two-cycle
engines are also disclosed.
When a polymer chain is functionalized with a hydroxyaromatic, it is well
known in the art to derivatize the alkylated hydroxyaromatic with an amine
in the presence of an aldehyde. This derivatization is known as a Mannich
Base reaction. In the present invention, dihydroxyaromatics may be
derivatized with amines without the use of an aldehyde--thereby saving the
expense of utilizing a reagent that is consumed in the reaction.
SUMMARY OF THE INVENTION
In the present invention, a dihydroxyaromatic compound is alkylated with a
polymer alkylating agent and then reacted with an amine under reaction
conditions effective in oxidizing the hydroxyl groups to carbonyl groups.
The preferred dihydroxyaromatic compounds are catechol and hydroquinone.
The products of the present invention demonstrate highly effective sludge
and varnish reducing properties when used as fuel and lubricant dispersant
additives.
DETAILED DESCRIPTION OF THE INVENTION
The process of the present invention may be described by the following
illustrative formulas wherein catechol, for example, is first alkylated
and then aminated with an amine:
##STR1##
wherein [O] indicates oxidation; POLY represents a polymer alkylating
agent which will react with the aromatic ring so as to attach as a
polymeric hydrocarbyl moiety (i.e., --POLY) thereto; and wherein HN-Amine
symbolizes a primary or secondary amine and the particular nitrogen moiety
thereof that takes part in the amination reaction; and wherein --N-Amine
symbolizes the amine bonded directly to the ring via the reacting nitrogen
atom as a result of the amination reaction.
Similarly, the final reaction product of the present invention wherein
hydroquinone is utilized may be represented by, for example, the following
formula:
##STR2##
though it is not required that the N-Amine and POLY moieties be
diametrically opposed as shown.
The reaction is unusual in that, unlike a Mannich Base reaction, no
formaldehyde is needed. Also unlike a Mannich Base is that the hydroxyl
groups are oxidized to carbonyl groups, the ring loses its aromaticity,
and the nitrogen atom bonds directly with the ring.
The resulting compositions are very effective as a dispersant in reducing
oil sludge and varnish in internal combustion engines.
The Dihydroxyaromatic Compounds
Dihydroxyaromatic compounds useful in the present invention include, but
are not limited to, hydroquinone, catechol, hydrocarbyl-substituted
dihydroxyaromatics such as methyl hydroquinone, ethylhydroquinone,
2-phenylhydroquinone, chlorohydroquinone, 3-methylcatechol,
4-methylcatechol, and the like. Also useful are dihydroxynapthols such as
1,4-dihydroxynaphthalene, 1,2-dihydroxynaphthalene and the like.
Dihydroxyaromatics useful in the present invention include those
represented by the following formulas:
##STR3##
wherein Q is a substituent comprising a halide radical, an aryl group,
hydrogen, a hydrocarbyl having 1 to 12 carbon atoms, or a structure of the
form:
##STR4##
and wherein Q' is defined as Q above, the same or different, and wherein
one or more sides may be shared with the moiety so substituted.
For the purposes of this invention, the term "hydrocarbyl" is not strictly
limited to moieties possessing solely carbon and hydrogen, but rather may
encompass a minor degree of substitution so long as the processes and
benefits of the invention are not thwarted thereby.
The Polymer Alkylating Agents
Polymer alkylating agents which are useful in the present invention are
polymers containing at least one carbon-carbon double bond unsaturation
(olefinic, or "ethylenic") and which are not so sterically hindered, or in
reactive competition with other functional groups, so as to render them
unable to participate in the catalytic alkylation of the chosen
dihydroxyaromatic compound. As long as a chosen double bond will react in
the presence of a chosen catalyst so as to alkylate a chosen
dihydroxyaromatic compound, such a bond will be deemed a "reactive"
unsaturation and the polymer possessing such an unsaturation will be
deemed a polymer alkylating agent.
Useful polymer alkylating agents in the present invention include
polyalkenes including homopolymer, copolymer (used interchangeably with
interpolymer) and mixtures thereof. Homopolymers and interpolymers include
those derived from polymerizable olefin monomers of 2 to about 16 carbon
atoms; usually 2 to about 6 carbon atoms. The interpolymers are those in
which two or more olefin monomers are interpolymerized according to
well-known conventional procedures to form polyalkenes having units within
their structure derived from each of said two or more olefin monomers.
Thus, "interpolymer(s)" as used herein is inclusive of terpolymers,
tetrapolymers, and the like. As will be apparent to those of ordinary
skill in the art, the polyalkenes from which the poly-substituent of
Formulas I and II are derived are often conventionally referred to as
"polyolefin(s)".
Useful polymers include those described in U.S. Pat. Nos. 4,234,435,
5,017,299, 5,186,851 and European Patent Application No. 0,462,319-A1.
Particular reference is made to the .alpha.-olefin polymers to be made
using organometallic coordination compounds as disclosed therein. A
particularly preferred class of polymers are ethylene/.alpha.-olefin
copolymers such as those disclosed in U.S. Pat. Nos. 5,017,299 and
5,186,851.
The preferred polymer alkylating agents for use in this invention possess
at least one carbon-carbon unsaturated double bond. The unsaturation can
be terminal, internal, or both. Preferred polymers have terminal
unsaturation. The polymers of the present invention preferably comprise a
high degree of terminal unsaturation. For the purposes of this invention,
"terminal unsaturation" refers to the unsaturation provided by the last
monomer unit located in the polymer. The unsaturation can be located
anywhere in this terminal monomer unit. Terminal olefinic groups include
ethenylidene (also known as "vinylidene") unsaturation, R.sup.a R.sup.b
C.dbd.CH.sub.2 ; trisubstituted olefin unsaturation, R.sup.a R.sup.b
C.dbd.CR.sup.c H; vinyl unsaturation, R.sup.a HC.dbd.CH.sub.2 ;
1,2-disubstituted terminal unsaturation, R.sup.a HC.dbd.CHR.sup.b ; and
tetra-substituted terminal unsaturation, R.sup.a R.sup.b C.dbd.CR.sup.c
R.sup.d. At least one of R.sup.a and R.sup.b is a polymeric group, and the
remainder are hydrocarbyl groups, polymeric or otherwise, the same or
different.
Especially preferred polymers for use in this invention exhibit substantial
terminal ethenylidene unsaturation. At least about 30%, preferably at
least about 50%, more preferably at least about 60%, and most preferably
at least about 75% (e.g., 75 to 98%), of such polymer chains exhibit
terminal ethenylidene unsaturation. Such polymers also may exhibit a minor
percentage of highly desirable ethenyl(vinyl) unsaturation, which may be
substituted for ethenylidene unsaturation in arriving at the percentages
disclosed above. Hence, for example, a combined percentage of 30%
ethenylidene and ethenyl unsaturation will more than adequately substitute
for 30% ethenylidene alone--and should even prove superior by virtue of
the higher reactivity of terminal ethenyl in comparison to that of
terminal ethenylidene.
The homopolymers and copolymers of the present invention can be
conveniently characterized based on molecular weight range. Polymers and
copolymers of "low", "intermediate" and "high" molecular weights can be
prepared.
Low molecular weight polymers, also referred to herein as
"dispersant-range" molecular weight polymers, are considered to be
polymers having a number average molecular weight of less than 20,000
(e.g., about 250 to about 20,000); preferably from at least 400 to about
20,000 (e.g., 450 to 1000; 500 to 2000; 700 to 3000; 1,000 to 19,000);
more preferably from about 1,500 to about 10,000 (e.g., 2,000 to 8,000);
and most preferably from 1,500 to 5,000. The low molecular weights are
number average molecular weights measured by vapor phase osmometry or gel
permeation chromatography (GPC). Low molecular weight polymers are useful
in the present invention for forming dispersants for fuel and lubricant
additives.
Medium molecular weight polymers, also referred to herein as
"viscosity-modifier-range" molecular weight polymers, have number average
molecular weights ranging from 20,000 to 200,000; preferably 25,000 to
100,000; and more preferably from 25,000 to 80,000 and are useful in the
present invention for making viscosity index improvers for lubricating oil
compositions, fuels, adhesive coatings, tackifiers and sealants. The
medium number average molecular weights can be determined by membrane
osmometry.
The high molecular weight materials have a number average molecular weights
of greater than about 200,000 and can range from 201,000 to 15,000,000; a
specific embodiment of 300,000 to 10,000,000; and more specifically
500,000 to 2,000,000. These polymers are useful in polymeric compositions
and blends including elastomeric compositions. Higher molecular weight
materials having number average molecular weights of from 20,000 to
15,000,000 can be measured by gel permeation chromatography with universal
calibration, or by light scattering as recited in Billmeyer, Textbook of
Polymer Science, Second Edition, pp. 81-84 (1971).
The values of the ratio Mw/Mn, also referred to as molecular weight
distribution, (MWD) are not critical. However, a typical minimum Mw/Mn
value of about 1.1 to 2.0 is preferred with typical ranges of about 1.1 up
to about 4.
Useful olefin monomers from which the polyalkenes can be derived are
polymerizable olefin monomers characterized by the presence of one or more
unsaturated double bonds (i.e., >C.dbd.C<); that is, they are monoolefinic
monomers such as ethylene, propylene, butene-1, isobutylene, and octene-1
or polyolefinic monomers (usually diolefinic monomers) such as
butadiene-1,3 and isoprene.
These olefin monomers are preferably polymerizable terminal olefins; that
is, they possess terminal unsaturation. However, polymerizable internal
olefin monomers (sometimes referred to as medial olefins) characterized by
the presence within their structure of the moiety:
##STR5##
can also be used to form the polyalkenes. When internal olefin monomers
are employed, they normally will be employed with terminal olefins to
produce polyalkenes which are interpolymers. For purposes of this
invention, when a particular polymerized olefin monomer can be classified
as both a terminal olefin and an internal olefin, it will be deemed to be
a terminal olefin. Thus, for example, pentadiene-1,3 (i.e., piperylene) is
deemed to be a terminal olefin for purposes of this invention.
While the polyalkenes generally are hydrocarbon polyalkenes, they can
contain substituted hydrocarbon groups such as lower alkoxy, lower alkyl
mercapto, hydroxyl, mercapto, and carbonyl, provided the non-hydrocarbon
moieties do not substantially interfere with the functionalization
reactions of this invention. Preferably, such substituted hydrocarbon
groups normally will not contribute more than about 10% by weight of the
total weight of the polyalkenes. Since the polyalkene can contain such
non-hydrocarbon substituent, it is apparent that the olefin monomers from
which the polyalkenes are made can also contain such substituents.
Normally, however, as a matter of practicality and expense, the olefin
monomers and the polyalkenes will be free from non-hydrocarbon groups. (As
used herein, the term "lower" when used with a chemical group such as in
"lower alkyl" or "lower alkoxy" is intended to describe groups having up
to seven carbon atoms.)
Although the polyalkenes may include aromatic groups--particularly phenyl
groups and lower alkyl- and/or lower alkoxy-substituted phenyl groups such
as para-(tertbutyl)phenyl--and cycloaliphatic groups, such as would be
obtained from polymerizable cyclic olefins or cycloaliphatic
substituted-polymerizable acrylic olefins, the polyalkenes usually will be
free from such groups. Again, because aromatic and cycloaliphatic groups
can be present, the olefin monomers from which the polyalkenes are
prepared can contain aromatic and cycloaliphatic groups.
There is a general preference for polyalkenes which are derived from the
group consisting of homopolymers and interpolymers of terminal hydrocarbon
olefins of 2 to about 16 carbon atoms. A more preferred class of
polyalkenes are those selected from the group consisting of homopolymers
and interpolymers of terminal olefins of 2 to about 6 carbon atoms, more
preferably 2 to 4 carbon atoms.
Specific examples of terminal and internal olefin monomers which can be
used to prepare the polyalkenes according to conventional, well-known
polymerization techniques include ethylene; propylene; butene-1; butene-2;
isobutylene; pentene-1; hexene-1; heptene-1; octene-1; nonene-1; decene-1;
pentene-2; propylene-tetramer; diisobutylene; isobutylene trimer;
butadiene-1,2; butadiene-1,3; pentadiene-1,2; pentadiene-1,3;
penta-diene-1,4; isoprene; hexadiene-1,5; 2-chloro-butadiene-1,2;
2-methyl-heptene-1; 3-cyclohexylbutene-1; 2-methyl-5-propyl-hexene-1;
pentene-3; octene-4; 3,3-dimethyl-pentene-1; styrene; 2,4-dichlorostyrene;
divinylbenzene; vinyl acetate; allyl alcohol; 1-methyl-vinyl acetate;
acrylonitrile; ethyl acrylate; methyl methacrylate; ethyl vinyl ether; and
methyl vinyl ketone. Of these, the hydrocarbon polymerizable monomers are
preferred and of these hydrocarbon monomers, the terminal olefin monomers
are particularly preferred.
Useful polymers include .alpha.-olefin homopolymers and interpolymers, and
ethylene/.alpha.-olefin copolymers and terpolymers. Specific examples of
polyalkenes include polypropylene, polybutene, ethylene-propylene
copolymer, ethylene-butene copolymer, propylene-butene copolymer,
styrene-isobutylene copolymer, isobutylene-butadiene-1,3 copolymer,
propene-isoprene copolymer, isobutylene-chloroprene copolymer,
isobutylene-(para-methyl)styrene copolymer, copolymer of hexene-1 with
hexadiene-1,3, copolymer of octene-1, copolymer of 3,3-dimethyl-pentene-1
with hexene-1, and terpolymer of isobutylene, styrene and piperylene. More
specific examples of such interpolymers include copolymer of 95% (by
weight) of isobutylene with 5% (by weight) of styrene; terpolymer of 98%
of isobutylene with 1% of piperylene and 1% of chloroprene; terpolymer of
95% of isobutylene with 2% of butene-1 and 3% of hexene-1; terpolymer of
60% of isobutylene with 20% of pentene-1; and 20% of octene-1; terpolymer
of 90% of isobutylene with 2% of cyclohexene and 8% of propylene; and
copolymer of 80% of ethylene and 20% of propylene.
A useful source of polyalkenes are the polybutylenes obtained by
polymerization of C.sub.4 refinery streams having a butene content of
about 35 to about 75% by weight and an isobutylene content of about 30 to
about 60% by weight in the presence of a Lewis acid catalyst such as
aluminum trichloride or boron trifluoride.
It must be noted, however, that polyisobutylene contains quarternary carbon
atoms in the polymer chain. Consequently, if the alkylating catalyst is
highly acidic (e.g., a heteropoly acid catalyst), highly stable tertiary
carbocations may form, thereby either cracking the polymer chain,
migrating inward from the terminus of the chain and thereby shifting the
location of the double bond, or some combination of both. Depending upon
the strength of the acid and the residence time of the reaction, one may
expect the Mn of the polyisobutyl chains of the alkylated hydroxyaromatics
to be substantially less than the Mn of the polyisobutylene starting
material and to find dimers, trimers and oligomers mixed in with the
reaction product.
The degradation of quarternary carbon-containing polymer alkylating agents
in the presence of strong acid catalyst is one reason why .alpha.-olefin
homopolymers and interpolymers as well as ethylene/.alpha.-olefin
copolymers and terpolymers are preferred.
Also useful are high molecular weight poly-n-butenes. Reference is made to
commonly assigned copending U.S. Ser. No. 992,871, filed Dec. 17, 1992
entitled, "Amorphous Olefin Polymers, Copolymers, Methods of Preparation
and Derivatives Thereof".
A preferred source of monomer for making poly-n-butenes is petroleum
feedstreams such as Raffinate-2. These feedstocks are disclosed in the art
such as in U.S. Pat. No. 4,952,739.
Preparing polyalkenes as described above which meet the various criteria
for Mn and Mw/Mn is within the skill of the art and does not comprise part
of the present invention.
Ethylene/.alpha.-olefin Copolymer
The most preferred polymers suitable for use as alkylating agents are
polymers of ethylene and at least one .alpha.-olefin, the .alpha.-olefin
typically having the formula H.sub.2 C.dbd.CHR.sup.4 wherein R.sup.4 is
straight chain or branched chain alkyl radical comprising 1 to 18 carbon
atoms and wherein the polymer contains a high degree of terminal
ethenylidene unsaturation. Preferably R.sup.4 in the above formula is
alkyl of from 1 to 8 carbon atoms and more preferably is alkyl of from 1
to 2 carbon atoms. Therefore, useful comonomers with ethylene in this
invention include propylene, butene-1, hexene-1, octene-1,
4-methylpentene-1, decene-1, dodecene-1, tridecene-1, tetradecene-1,
pentadecene-1, hexadecene-1, heptadecene-1, octadecene-1, nonadecene-1 and
mixtures thereof (e.g., mixtures of propylene and butene-1, and the like).
Preferred polymers are copolymers of ethylene and propylene and ethylene
and butene-1.
The ethylene content of the polymers employed is preferably in the range of
between about 20 and about 80%, and more preferably between about 30 and
about 70% by mole. When butene-1 is employed as comonomer with ethylene,
the ethylene content of such copolymer is most preferably between about 20
and about 45% by weight, although higher or lower ethylene contents may be
present.
Preferred ethylene/butene-1 copolymers are disclosed in U.S. Pat. No.
5,498,809 titled POLYMERS DERIVED FROM ETHYLENE AND 1-BUTENE FOR USE IN
THE PREPARATION OF LUBRICANT DISPERSANT ADDITIVES, wherein is disclosed an
oil soluble copolymer comprising from 1 to about 50 weight percent monomer
units derived from ethylene and from about 99 to about 50 weight percent
monomer units derived from butene-1, based on the total polymer weight,
and having a number average molecular weight between about 1,500 and
7,500, ethylvinylidene groups terminating at least about 30 percent of all
copolymer chains, and an absence of aggregation in solution with mineral
oil as determined by having an S.sub.f value(light-scattering factor) of
about zero.
A preferred method for making ethylene/.alpha.-olefin copolymer is
described in commonly assigned U.S. Ser. No. 257,398, filed Jun. 9, 1994,
which is a continuation of U.S. Ser. No. 992,690, filed Dec. 17, 1992,
(abandoned) and is titled DILUTE PROCESS FOR THE POLYMERIZATION OF
ETHYLENE/.alpha.-OLEFIN COPOLYMER USING METALLOCENE CATALYST SYSTEMS,
wherein there is described a process for continuously producing copolymer
comprising monomer units derived from ethylene and .alpha.-olefin in the
presence of a metallocene catalyst system and in a reaction zone
containing liquid phase which comprises (A) continuously providing a
dilute liquefied .alpha.-olefin feed stream comprising at least one
.alpha.-olefin reactant and diluent admixed therewith wherein the amount
of diluent in said feed stream is at least 30% weight percent thereof; (B)
providing a feed stream comprising ethylene in liquid, vapor, or
liquid/vapor form; (C) admixing, the feed streams of steps (A) and (B) in
amounts sufficient to provide a reactant feed stream having an
.alpha.-olefin/ethylene weight ratio effective to yield a copolymer
containing between about 5 to about 70 weight percent monomer units
derived from ethylene; (D) continuously introducing reactant feed stream
derived in accordance with step (C) and metallocene catalyst system into
the liquid phase of the reaction zone in a manner and under conditions
sufficient to: (i) polymerize the ethylene and .alpha.-olefin to polymer
product having a number average molecular weight of not greater than about
15,000 (ii), obtain an .alpha.-olefin conversion of at least 30%, and
(iii) obtain an ethylene conversion of at least 70%; and (E) continuously
withdrawing copolymer product from the reactor.
The ethylene/.alpha.-olefin polymers generally possess a number average
molecular weight as recited. Preferred ranges of molecular weights of
polymer for use as precursors for dispersants are from about 500 to about
10,000, preferably of from about 1,000 to about 8,000, most preferably of
from about 2,000 to about 6,000. The number average molecular weight for
such polymers can be determined by several known techniques. A convenient
method for such determination is by size exclusion chromatography (also
known as gel permeation chromatography, or GPC) which additionally
provides molecular weight distribution information, see W. W. Yau, J. J.
Kirkland and D. D. Bly, "Modern Size Exclusion Liquid Chromatography",
John Wiley and Sons, New York, 1979. Such polymers generally possess an
intrinsic viscosity (as measured in tetralin at 135.degree. C.) of between
about 0.025 and about 0.6 dl/g, preferably of between about 0.05 and about
0.5 dl/g, most preferably of between about 0.075 and about 0.4 dl/g. These
polymers preferably exhibit a degree of crystallinity such that, when
functionalized, they are oil soluble.
The preferred ethylene/.alpha.-olefin polymers are further characterized in
that the polymer chains possess as much terminal ethenylidene- and
ethenyl-type unsaturation as possible. Thus, one end of such polymers will
be of the formula POLY'--C(R").dbd.CH.sub.2 wherein R" is C.sub.1 to
C.sub.18 alkyl, preferably C.sub.1 to C.sub.8 alkyl, and more preferably
C.sub.1 to C.sub.2 alkyl, (e.g., methyl or ethyl) and wherein POLY'
represents the polymer chain; and a minor amount of the polymer chains may
contain terminal ethenyl (i.e., "vinyl") unsaturation, i.e.,
POLY'--CH.dbd.CH.sub.2. The chain length of the R" alkyl group will vary
depending on the comonomer(s) selected for use in the polymerization. A
portion of the polymers can contain internal monounsaturation, e.g.,
POLY'--CH.dbd.CH(R"), wherein R" is as defined above.
Preferred ethylene/.alpha.-olefin polymer comprises polymer chains, at
least about 30% of which possess terminal ethenylidene unsaturation.
Preferably at least about 50%, more preferably at least about 60%, and
most preferably at least about 75% (e.g., 75 to 98%), of such polymer
chains exhibit terminal ethenylidene unsaturation. The percentage of
polymer chains exhibiting terminal ethenylidene unsaturation may be
determined by FTIR spectroscopic analysis, titration, HNMR, or C-13NMR.
Such polymers also generally exhibit a minor percentage of highly
desirable ethenyl (vinyl) unsaturation, which may be substituted for
ethenylidene unsaturation in arriving at the percentages disclosed above.
Hence, for example, a combined percentage of 30% ethenylidene and ethenyl
unsaturation will more than adequately substitute for 30% ethenylidene
alone--and should even prove superior by virtue of the higher reactivity
of terminal ethenyl in comparison to that of terminal ethenylidene.
The ethylene/.alpha.-olefin polymer and the compositions employed in this
invention may be prepared as described in U.S. Pat. No. 4,668,834, in
European Patent Publications 128,046 and 129,368, and in U.S. Pat. Nos.
5,324,800 and 5,084,534.
The polymers can be prepared by polymerizing monomer mixtures comprising
ethylene in combination with other monomers such as .alpha.-olefins having
from 3 to 20 carbon atoms (and preferably from 3 to 4 carbon atoms, i.e.,
propylene, butene-1, and mixtures thereof) in the presence of a
metallocene catalyst system comprising at least one metallocene (e.g., a
cyclopentadienyl-transition metal compound) and an activator, e.g.,
alumoxane compound. The comonomer content can be controlled through the
selection of the metallocene catalyst component and by controlling the
partial pressure of the various monomers.
The polymer for use in the present invention can include block and tapered
copolymers derived from monomers comprising at least one conjugated diene
with at least monovinyl aromatic monomer, preferably styrene. Useful
polymers include polymers of the type disclosed in U.S. Pat. Nos.
4,073,737 and 3,795,615.
Such polymers should not be completely hydrogenated so that the polymeric
composition contains terminal olefinic double bonds, preferably at least
one bond per molecule. Useful polymers include an oil soluble copolymer of
the following general formula:
(A).sub.x (B).sub.y ( 4)
wherein:
A is a conjugated diene of the formula:
##STR6##
wherein R.sup.9 is a H or C.sub.1 to C.sub.8 alkyl group, preferably H or
CH.sub.3 (i.e., isoprene) and present in mole % proportion as indicated by
x which may vary from 45 to 99 mole %;
B is a C.sub.8 to C.sub.20 monovinyl aromatic compound and/or aromatic
substituted diene and present in weight % proportion as indicated by y
which may vary from 1 to 55 mole %; typically from 25 to 30 mole %, and
preferably from 5 to 40 mole %. The lattermost range representing where
the most useful composite properties of oxidative stability and
-18.degree. C. viscosity of the lubricating oil blend is realized.
Block copolymers as used herein includes "multiple block copolymers" which
term denotes copolymers consisting of two or more of the single block
copolymers described above, which are bound to each other. A multiple
block copolymer may, for example, be prepared by first copolymerizing to
completion a mixture of butadiene and isoprene, thereafter polymerizing
styrene onto said copolymer and subsequently sequentially copolymerizing a
mixture of butadiene and isoprene followed by said styrene onto the
"living" block copolymer. For purposes of this disclosure, a "living"
copolymer is one which remains stable over an extended period of time
during which additional monomers can be added to it.
Multiple block copolymers can also be obtained in other ways such as by
coupling of two or more "living" block copolymer molecules. This can be
achieved by addition of a compound which reacts with two or more "living"
single block copolymer molecules. Examples of this type of compound
include compounds containing two or more ester groups, compounds with more
than one active halogen atom, e.g., di- and tri-chloromethyl-benzene,
phosgene, dichlorosilane, carbon tetrachloride, dimethyldichlorosilane,
1,2-dichloroethane, 1,2-dibromo-methane, and the like. Another possible
method for preparing multiple block copolymers consists in the preparation
of single block copolymer containing a reactive group in the molecule
(e.g., a carboxyl group, which is, for example, obtained by bringing the
polymerization of a single copolymer to an end by addition of carbon
dioxide) and coupling of two or more of the molecules, e.g., by
esterifying them with a di- or polyvalent alcohol. Multiple block
copolymers have the further advantage that they can be tailored to provide
the most useful additive properties while masking one or more undesirable
properties inherent in any polymer block.
The present invention can also include star polymers as disclosed in
patents such as U.S. Pat. Nos. 5,070,131; 4,108,945 and 3,711,406 as well
as 5,049,294. Particularly useful star polymers are disclosed in U.S. Pat.
No. 5,070,131.
The Alkylation of the Dihydroxyaromatics
The alkylation of the dihydroxyaromatic compounds may be carried out by
methods known in the art, as by the use of acid catalysts such as sulfuric
acid, boron trifluoride and aluminum chloride such as described in U.S.
Pat. No. 4,735,582, and EP Publication 440,507 A2. Such catalysts are
often referred to as "homogeneous" catalysts because they either dissolve
into the reaction mixture or are liquid at reaction temperature and
pressure.
Preferred alkylation catalysts are the so called "heterogeneous" catalysts.
Such catalysts remain solid during the alkylation and are therefore easy
to separate from the product mixture. Suitable heterogeneous catalysts
include zeolites, as are disclosed in U.S. Pat. Nos. 4,283,573; 4,731,497
and 4,954,663; mole sieves and exchange resins such as are described in
U.S. Pat. Nos. 4,323,714 and 4,849,569 and EP Publication 387,080; clays,
layered materials and composites thereof such as are described in UK
Patent Application 2,120,953 and EP Application 400,857; and hydrated
heteropoly acids and excess water as is described in U.S. Pat. No.
4,912,264. Supported heteropoly acids such as are described in U.S. Pat.
No. 3,346,657 are also suitable. Amberlyst 15 is also a preferred
heterogeneous catalyst.
A particularly preferred catalyst is a dehydrated heteropoly catalyst as
described in Gutierrez et al., POLYMER ALKYLATION OF HYDROXYAROMATIC
COMPOUNDS, U.S. Pat. No. 5,334,775 wherein there is disclosed a process
for alkylating hydroxyaromatic compounds comprising contacting, in the
liquid phase, a hydroxyaromatic compound, a polymer alkylating agent of at
least about 500 average number molecular weight and having at least one
reactive carbon-carbon double bond unsaturation, and a heteropoly catalyst
having substantially no waters of crystallization per heteropolyanion
therein. Such catalysts include phosphomolybdic acid, silicomolybdic acid,
arsenomolybdic acid, telluromolybdic acid, aluminomolybdic acid,
silicotungstic acid, phosphotungstic acid, borotungstic acid,
titanotungstic acid, stannotungstic acid, and salts thereof. The catalyst
is prepared for the reaction by driving water of hydration and
crystallization out of the catalyst, either before or during the
alkylation. Advantages include the ability to easily alkylate
hydroxyaromatics with polymer alkylating agents having molecular weights
well over 1000. Reaction temperatures vary from about 20.degree. C. to
250.degree. C., but will be conducted above the boiling point of water in
cases where water needs to be driven out of the catalyst during
alkylation.
Alkylation of dihydroxyaromatic compounds in the presence of Amberlyst 15
are typically carried out at temperatures from 10.degree. to 150.degree.
C., generally 20.degree. to 120.degree. C., preferably 80.degree. to
110.degree. C. for reaction times of from 0.5 to 24 hours, generally 1 to
12 hours, preferably 2 to 6 hours.
The Amines
The amines useful in the present invention are polyamines having at least
one primary or secondary amine group.
Preferred polyamines are aliphatic saturated amines, including those of the
following structural formulas:
##STR7##
wherein n is an integer of at least 1 and R', R", R'", and R.sup.IV are
independently selected from the group consisting of hydrogen; C.sub.1 to
C.sub.25 straight or branched chain alkyl radicals; C.sub.1 to C.sub.12
alkoxy C.sub.2 to C.sub.6 alkylene radicals; C.sub.2 to C.sub.12 hydroxy
amino alkylene radicals; and C.sub.1 to C.sub.12 alkylamino C.sub.2 to
C.sub.6 alkylene radicals; and wherein R" and R'" can additionally
comprise a moiety of the formula:
##STR8##
wherein R' is as defined above, and wherein each s and s' can be the same
or a different number of from 2 to 6, preferably 2 to 4; and t and t' can
be the same or different and are each numbers of typically from 0 to 10,
preferably about 2 to 7, most preferably about 3 to 7, with the proviso
that t+t' is not greater than 10. To assure a facile reaction it is
preferred that R', R", R'", R.sup.IV, s, s', t, and t' be selected in a
manner sufficient to provide the compounds of formulas IV and V with at
least one primary amino group. This can be achieved by selecting at least
two of said R', R", or R.sup.IV groups in formula IV to be hydrogen,
selecting both R' and R.sup.IV in formula V to be hydrogen, or by
selecting t in formula V to be at least one when the moiety of formula VI
possesses a primary amino group.
Non-limiting examples of suitable amine compounds include:
1,2-diaminoethane; 1,3-diaminopropane; 1,4-diaminobutane;
1,6-diaminohexane; polyethylene amines such as diethylenetriamine (DETA);
triethylene tetramine; tetraethylene pentamine; polypropylene amines such
as 1,2-propylene diamine; di-(1,2-propylene)triamine; di-(1,3-propylene)
triamine; N,N-dimethyl-1,3-propanediamine (also known as
N,N-dimethylaminopropylamine, or DMAPA); N,N-di-(2-aminoethyl) ethylene
diamine; N,N-di-(2-hydroxyethyl)-1,3-propylene diamine;
N-dodecyl-1,3-propane diamine; and mixtures thereof.
Other useful amine compounds include: alicyclic diamines such as
1,4-di-(aminoethyl)cyclohexane, and N-aminoalkyl piperazines of the
general formula:
##STR9##
wherein p1 and p2 are the same or different and are each integers of from
1 to 4, and n1, n2, and n3 are the same or different and are each integers
of from 1 to 3.
Commercial mixtures of amine compounds may advantageously be used. For
example, one process for preparing alkylene amines involves the reaction
of an alkylene dihalide (such as ethylene dichloride or propylene
dichloride) with ammonia, which results in a complex mixture of alkylene
amines wherein pairs of nitrogens are joined by alkylene groups, forming
such compounds as diethylene triamine, triethylenetetramine, tetraethylene
pentamine, and corresponding piperazines.
Particularly preferred amines include low cost poly(ethyleneamine)
compounds, often referred to as PAM, averaging about 5 to 7 nitrogen atoms
per molecule. These are commercially available under trade names such as
"Polyamine H", "Polyamine 400", "Dow Polyamine E-100", among others.
Also useful are polyoxyalkylene polyamines, such as those of the formula:
NH.sub.2 -alkylene-(-O-alkylene-).sub.m --NH.sub.2 (VIII)
where m has a value of about 3 to about 70 and preferably about 10 to about
35; and
R.sup.4 -[-alkylene-(-O-alkylene-).sub.n --NH.sub.2 ].sub.a(IX)
where n has a value of about 1 to 40, with the provision that the sum of
all the n's is from about 3 to about 70, and preferably from about 6 to
about 35, and R.sup.4 is a substituted saturated hydrocarbon radical of up
to 10 carbon atoms, wherein the number of substituents on the R.sup.4
group is from 3 to 6, and "a" is a number from 3 to 6 representing the
number of substituents on R.sup.4. The alkylene groups in either formula
VIII or IX may be straight or branched chains containing about 2 to about
7, and preferably about 2 to about 4 carbon atoms.
Particularly preferred polyamine compounds include the polyoxyalkylene
polyamines of formulas VIII and IX, and the alkylene polyamines
represented by the formula:
##STR10##
wherein x is an integer of from 1 to about 10, preferably about 2 to about
7, and the alkylene radical is a straight or branched chain alkylene
radical having about 2 to about 7, preferably about 2 to about 4 carbon
atoms.
Examples of the alkylene polyamines of formula X include methylene amines,
ethylene amines, butylene amines, propylene amines, pentylene amines,
hexylene amines, heptylene amines octylene amines, other polymethylene
amines, the cyclic and higher homologs of these amines such as the
piperazines, the amino-alkyl-substituted piperazines, and the like. These
amines include, for example, ethylene diamine, diethylene triamine,
triethylene tatramine, propylene diamine, di(heptamethylene)triamine,
tripropylene tetramine, tetraethylene pentamine, trimethylene diamine,
pentaethylene hexamine, di(trimethylene) triamine,
2-heptyl-3-(2-aminopropyl)imidazoline, 4-methylimidazoline,
1,3-bis-(2aminopropyl)piperazine, 1,4-bis (2-aminoethyl) piperazine, N,
N-dimethylaminopropylamine (DMAPA), N,N'-dioctylethylamine,
N-octyl-N'-methylethylene diamine, 2-methyl-1-(2-aminobutyl)piperazine,
and the like. Other higher homologs which may be used can be obtained by
condensing two or more of the above-mentioned alkylene amines in a known
manner.
The ethylene amines which are particularly useful are described, for
example, in the Encyclopedia of Chemical Technology under the heading of
"Ethylene Amines" (Kirk and Othmer), Volume 5, pp. 898-905; Interscience
Publishers, New York (1950). These compounds are prepared by the reaction
of an alkylene chloride with ammonia, which results in the production of a
complex mixture of alkylene amines, including cyclic condensation products
such as piperazines. Mixtures of these amines may also be used for the
purposes of this invention.
The polyoxyalkylene polyamines of formulas VIII and IX, preferably
polyoxyalkylene diamines and polyoxyalkylene triamines, may possess
average molecular weights ranging from about 200 to about 4000 and
preferably from about 400 to about 2000. The preferred polyoxyalkylene
polyamines include the polyoxyethylene and the polyoxypropylene diamines
and the polyoxypropylene triamines having average molecular weights
ranging from about 200 to about 2000. The polyoxyalkylene polyamines are
commercially available and may be obtained, for example, from the
Jefferson Chemical Company, Inc. under the trade names "Jeffamines D-230,
D-400, D-1000, D-2000, T-403", etc.
The Amination Reaction Conditions
Without limiting the present invention to a particular theory, it is
believed that an alkylated quinone-type (i.e., dicarbonyl) intermediate is
created (e.g., an alkylated 1,4-benzoquinone in the case where
hydroquinone is used as the dihydroxyaromatic; an alkylated
1,2-benzoquinone in the case of catechol) during the reaction that is then
subsequently aminated. It is therefore possible to use alkylated
dicarbonyl analogues of the dihydroxyaromatics of the present invention as
starting material and aminate them directly in accordance with the methods
disclosed herein.
It is preferred that the reaction mixture be exposed to an oxidizing agent
such that the alkylated dihydroxyaromatic is oxidized to the corresponding
alkylated dicarbonyl intermediate. The dicarbonyl then reacts with the
amine. Simple exposure to atmospheric oxygen during the reaction is
sufficient for this purpose, though other oxidizing agents may be
employed. The alkylation, oxidation, and amination steps may be easily
followed by spectroscopic techniques such as infrared or NMR spectroscopy.
Failure to use an oxidizing agent will result in poor yields, since it may
be expected that one molecule of reactant will be consumed in order to
oxidize another to form one molecule of final product.
The amination of the present invention is preferably performed in an inert
solvent, such as a hydrocarbon. Useful hydrocarbons include heptane,
cyclohexane, toluene, xylene, mineral oil, and the like.
The alkylated dihydroxyaromatic compound, primary amine, and solvent are
mixed and will generally be reacted at a temperature of from 0.degree. to
200.degree. C., preferably 10.degree. to 110.degree. C. (e.g., 20.degree.
to 100.degree. C.), for a period of from 0.5 to 168 hours, preferably 1 to
48 (e.g., 1.5 to 12; 2 to 6) hours.
Depending upon such factors as the reactants chosen and the nitrogen
content of the final product desired, the amines of the present invention
will generally be employed in the amount of from 0.01 mole of amine per
mole of dihydoxyaromatic to 10 moles of amine per mole of
dihydoxyaromatic, preferably 0.1 to 5 moles of amine per mole of
dihydroxyaromatic (e.g., 0.3 to 2; 0.5 to 1).
Lubricant Compositions
The products prepared by the process of this invention are very suitable
for use in lubricating oils. The lubricating oils can be any animal,
vegetable or mineral oil, for example petroleum oil to SAE 30, 40 or 50
lubricating oil grades, castor oil, fish oils or oxidized mineral oils.
Alternatively the lubricating oil can be a synthetic ester lubricating oil
and these include diesters such as dioctyl adipate, di-octyl sebacate,
didecyl azelate, tridecyl adipate, didecyl succinate, didecyl glutarate
and mixtures thereof. Alternatively the synthetic ester can be a polyester
such as that prepared by reacting polyhydric alcohols such as
trimethylolpropane and pentaerythritol with monocarboxylic acids such as
butyric acid to give the corresponding tri- and tetra-esters. Also complex
esters may be used, such as those formed by esterification reactions
between carboxylic acid, a glycol and an alcohol, or monocarboxylic acid.
Base oils suitable for use in preparing the lubricating oil compositions of
the present invention include those conventionally employed as crankcase
lubricating oils for spark-ignited and compression-ignited internal
combustion engines, such as automobile and truck engines, marine and
railroad diesel engines, and the like. Advantageous results are also
achieved by employing the products of the present invention in base oils
conventionally employed in and/or adapted for use as power transmitting
fluids such as automatic transmission fluids, tractor fluids, universal
tractor fluids and hydraulic fluids, heavy duty hydraulic fluids, power
steering fluids and the like. Gear lubricants, industrial oils, pump oils
and other lubricating oil compositions can also benefit from the
incorporation therein of the products of the present invention.
The amount of product alkylated with dispersant-range molecular weight
polymer alkylating agent added to a lubricating oil is typically a minor
proportion and will generally be blended in proportions of from 0.01% to
30% by weight of lubricating oil (e.g., 0.01% to 20% by weight),
preferably between 0.1% and 8% by weight (e.g., 0.1% to 5% by weight).
The amount of product alkylated with viscosity-modifier-range molecular
weight polymer alkylating agent added to a lubricating oil is typically a
minor proportion and will generally be blended in proportions of from
0.01% to 20% by weight of lubricating oil (e.g., 0.01% to 12% by weight),
preferably between 0.01% and 6% by weight (e.g., 0.01% to 4% by weight).
The products of the present invention may be borated by means known in the
art.
Fuel Compositions
The products of this invention are suitable for use in normally liquid
petroleum fuels such as middle distillates boiling from about 65.degree.
C. to 430.degree. C., including kerosene, diesel fuels, home heating fuel
oil, and jet fuels.
The amount of product alkylated with dispersant-range molecular weight
polymer alkylating agent added to a fuel oil is typically a minor
proportion and will generally be blended in proportions of from 0.001% to
0.5% by weight of fuel oil (e.g., 0.001% to 0.3% by weight), preferably
between 0.001% and 0.15% by weight (e.g., 0.005% to 0.1% by weight).
The final fuel and lubricating oil compositions may if desired contain
other additives known in the additive art, e.g., other viscosity index
improvers and dispersants, detergents, antioxidants, corrosion inhibitors,
pour point depressants, antiwear agents, friction modifiers, and the like.
EXAMPLES
Examples 1 to 5
Alkylation of Hydroquinone
In each of Examples 1 through 5, a quantity of hydroquinone (MW=110) was
dissolved in a quantity of either heptane or toluene and charged to a 250
ml. round-bottom flask. A quantity of Amberlite-15 (a strongly acidic
resin comprising divinylbenzene-crosslinked polystyrene, to which sulfonic
groups are attached) was added, followed by the addition of a quantity of
an ethylene/propylene copolymer ("EP polymer") having a number average
molecular weight of 870 and terminal unsaturation. Each reaction mixture
was then heated for a number of hours and then filtered, followed by the
removal of the solvent under vacuum.
IR spectra of the products revealed new peaks appearing at 3600 and 1400
cm.sup.-1 (thereby indicating a change in the nature of the hydrxyl groups
on the aromatic ring that would indicate the presence of a substituent
thereon) and complete disappearance of the double bond peaks of the EP
polymer at 3065, 1645 and 885 cm.sup.-1 (thereby indicating the loss of
the polymer unsaturation). This indicates that the dihydroxyaromatic was
successfully alkylated.
The alkylation procedures are shown in Table I as follows:
TABLE I
__________________________________________________________________________
Hydroquinone Solvent
Amberlite
EP RX Temp
RX Time
Ex. No.
g. Solvent
ml. g. g. .degree.C.
hrs.
__________________________________________________________________________
1 6.32 Hep 50 12.5 25 98 6.0
2 30.00 Tol 50 15.0 50 90 2.0
3 3.16 Hep 30 15.0 50 90 2.5
4 6.32 Hep 30 15.0 50 90 2.5
5 12.64 Hep 30 15.0 50 90 2.5
__________________________________________________________________________
Example 6
Alkylation of Catechol
Into a 250 ml. round-bottom flask were charged 6.32 g. (0.0575 moles) of
Catechol (MW=110) and 50 ml of toluene. To this was added 10 g. of
Amberlite-15 and the mixture was heated to 90.degree. C. Added to this was
50 g. of an EP polymer (MW=870) and the solution was maintained at
90.degree. C. for another 2 hours. The reaction mixture was then filtered,
the filtrate evaporated, and the resultant product redissolved in heptane.
The heptane solution was itself filtered and the filtrate evaporated under
vacuum to obtain the product.
Examples 7 through 12
Amination of Alkylated Hydroquinone with PAM
In each of examples 7 through 12, 2 g. of the EP-hydroquinone produced in
Example 5 were dissolved in 50 ml heptane. To this was added a quantity of
either PAM (polyethyleneamine having an average of 5 to 7 nitrogen atoms
per molecule),DETA (diethylenetriamine, MW=103), or DMAPA
(N,N-dimethylaminopropylamine, MW=103). Each solution was stirred at room
temperature for 24 hours and then diluted with 50 ml of heptane and
filtered. The solvent was removed by nitrogen stripping followed by
evaporation under high vacuum. The products were analyzed for nitrogen
content.
The results are summarized in Table II as follows:
TABLE II
______________________________________
Nitrogen
Amine Content
Ex. No. Amine g. wt. %
______________________________________
7 PAM 0.150 2.18
8 PAM 0.300 3.27
9 DETA 0.103 1.58
10 DETA 0.206 2.65
11 DMAPA 0.103 0.33
12 DMAPA 0.206 0.40
______________________________________
Example 13
Amination of Alkylated Catechol with DMAPA
4.32 g. of the product of Example 6 were dissolved in 50 ml of heptane. To
this mixture was added 0.9 g. of DMAPA and the solution was refluxed for 6
hours at 98.degree. C. Afterwards, the heptane was removed by nitrogen
stripping followed by evaporation under high vacuum.
The nitrogen content of the product was found to be 1.20 wt. %.
Dispersancy Performance
The performance of the products of Examples 7 through 13 were tested for
sludge inhibition and varnish inhibition as described herein.
The test for sludge inhibition is referred to as the SIB test. The SIB test
has been found to be excellent for assessing the dispersing power of
lubricating oil dispersant additives.
The medium chosen for the SIB test is a crankcase mineral lubricating oil
composition having an original viscosity of about 325 SUS at 38.degree. C.
that has been used in a taxicab driven for short trips only, thereby
resulting in the buildup of high concentrations of sludge precursors. The
oil used in the taxi contains only a refined base mineral lubricating oil,
a viscosity index improver, a pour point depressant, and a zinc
dialkyl-dithiophosphate anti-wear additive. The oil contains no sludge
dispersant. A quantity of such used oil is acquired by draining and
refilling the taxicab crankcase at 1,000 to 2,000 mile intervals.
The SIB test is conducted by first taking the aforesaid used crankcase oil
from the taxi and centrifuging the milky brown fluid for 1 hour at about
39,000 gravities (gs). The resultant clear bright red supernatant oil is
decanted from the sludge particles. The sludge has been removed from this
supernatant but it still contains sludge precursors, which upon heating
will convert to additional sludge.
A small amount of each dispersant being tested is then added to a quantity
of the supernatant and heated at 135.degree. C. for 16 hours in the
presence of air. A sample of the supernatant without any dispersant added
is used as the standard, while a sample having a well known commercially
available dispersant blended therein is often used as a reference. After
heating, the samples are cooled to room temperature and centrifuged at
about 39,000 gs. Any sludge removed by this step is separated by decanting
the resulting supernatant and washing the precipitate with heptane,
followed by additional cetrifugation. The sludge precipitate is then dried
and weighed.
The SIB score is determined by comparison with the standard (the sample
having no dispersant). The weight of the sludge precipitate removed from
the standard is normalized to 10. The amount of sludge precipitated from
the other samples are scored by weight. Hence, if the precipitate from the
standard were found to have weighed 22 grams, for example, and the
precipitate from a particular dispersant sample weighed 11 grams, then the
dispersant sample scores 5 after normalization of the standard to 10. As
can be seen, the lower the SIB score, the better the sludge deposit
inhibition qualities of the dispersant.
An SIB score greater than 10 indicates that the additive being tested
demonstrates worse sludge deposit inhibition qualities than no additive at
all. Such an additive would be classified as a flocculant.
The VIB test is used to determine varnish inhibition. Here, small
quantities of dispersant are added to a supernatant oil having sludge
precursors, just as described above with respect to the SIB test. Each
sample is heat soaked overnight at about 140.degree. C. and then
centrifuged to remove the sludge precipitate. The precipitate is removed
and the supernatant is then subjected to heat cycling of from room
temperature to 150.degree. C. at a frequency of about 2 cycles per minute
over a 3.5 hour period. During the heating phase of each cycle, a gas
comprising 0.7% SO.sub.2 by volume, 1.4% NO by volume, and the remainder
air, is bubbled through each test sample. These cycling periods may be
repeated as necessary.
After heat cycling, the flasks in which the samples are contained are
visually examined for varnish deposits. The samples are subjectively rated
against the standard on a scale of 1 to 11, wherein a score of 1 indicates
no varnish deposits at all and the standard (having no dispersant) is
given a rating of 11. Hence, the lower the score, the better the varnish
inhibition qualities of the dispersant.
A VIB score greater than 11 indicates that the varnish inhibition qualities
of the tested additive are worse than no additive at all.
The reference used in the table below was a PIBSA-PAM dispersant wherein
the polyisobutylene moiety had a number average molecular weight of about
950, the number of succinimide moieties to each polyisobutylene chain was
about 1.18, and the nitrogen content of each molecule averaged 1.59% by
weight. The reference is considered representative of dispersants
currently in commercial use.
The results of SIB and VIB tests on the products of Examples 7 through 13
were as follows:
TABLE III
______________________________________
Example No. SIB mg VIB rating
______________________________________
7 7.1 4
8 8.5 4
9 8.0 5+**
10 8.5 4
11 5.85 5-**
12 5.75 6
13 1.59 4
Reference* 4.20 .+-. 0.68
7 .+-. 0
Standard 10.00 11.00
______________________________________
*the catecholand hydroquinonederived dispersants were evaluated in two
separate sets of SIB and VIB tests using two separate samples of
supernatant crankcase oil. Hence, the reference score for each test is no
exactly the same. Here, the two scores from the SIB tests and the two
scores from the VIB tests were averaged.
**A "+" indicates a slightly higher value, a "-" slightly lower. No
attempt at greater accuracy is made since the evaluation is necessarily
subjective.
As can be seen, the catechol derived dispersant (Example 13) displayed the
most impressive sludge-reducing properties and significant varnish
reducing properties over the reference. Hydroquinone-derived dispersants
(Examples 7 to 12) showed improved varnish reduction over the reference.
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